Systems and methods of safeguarding user information while interacting with online service providers

ABSTRACT

The disclosed technology includes techniques for improving data privacy in mobile communications over public cloud services. According to certain implementations, a novel conceptual layer may be interposed between the “application” layer and the “user” layer. In some implementations, the conceptual layer may be at least partially embodied by a transparent window or pane overlaid on top of existing app graphical user interfaces to: (1) intercept plaintext user input before transforming the input and feeding it to an underlying app; and (2) reverse transform output data from the app before displaying the plaintext data to the user. Accordingly, the conceptual layer may serve as a protective layer while preserving the original application workflow and look-and-feel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and the benefit under 35 U.S.C.§119(e), of U.S. Provisional Patent Application No. 61/890,513, filed 14Oct. 2013, the entire contents and substance of which are herebyincorporated by reference as if fully set forth below.

STATEMENT OF RIGHTS UNDER FEDERALLY-SPONSORED RESEARCH

The disclosed technology was made in part with U.S. Government supportunder Grant Nos. CNS-1017265, CNS-0831300, CNS-1149051, and CNS-1318511,awarded by the National Science Foundation; Grant No. N000140911042,awarded by the Office of Naval Research; Contract No. N66001-12-C-0133,awarded by the Department of Homeland Security; and Contract No.FA8650-10-C-7025, awarded by the United States Air Force. The U.S.Government has certain rights in the invention.

BACKGROUND

A growing number of users are utilizing mobile computing devices toaccess public cloud services (PCS) (e.g., Gmail™, Outlook®, andWhatsApp®) as an essential part of their daily lives. While mobileplatforms may help improve a user's connectivity to the Internet, theissue of preserving data privacy while accessing PCS on mobile devicesremains unsolved. Moreover, recent news about widespread governmentalsurveillance programs has brought to the forefront a very unsatisfactorystatus quo: while PCS have become an essential part of everyday life formany, conventional methods of accessing PCS expose users to privacybreaches because they implicitly require the users to trust the PCSproviders with the confidentiality of user data. However, such trust isunjustified, if not misplaced. In many situations, PCS providers arebound by law to share their users' data with surveillance agencies.Moreover, it is the business model of many PCS providers to mine theirusers' data and share it with third parties. Further, operator error mayresult in unintended data leaks, and data servers may be compromised byattackers.

To alter this undesirable status quo, solutions should be designed basedon an updated trust model of everyday communications that betterreflects the reality of these threats. In particular, new solutionsshould assume PCS providers untrustworthy. This implies that all otherentities controlled by the PCS providers—including the consumer appsthat users install to engage with the PCS—should also be assumeduntrustworthy.

SUMMARY

The above needs and others may be addressed by certain implementationsof the disclosed technology. Certain implementations include techniquesfor improving data privacy in mobile communications over public cloudservices.

According to an example implementation, a method is provided. The methodmay include receiving, at a processor, private data (which can betextual or multi-media) corresponding to first user input at an inputdevice operatively coupled to the processor. The private data may beformatted for entry into a GUI of a data communications software runningon a computing device. The GUI may be being displayed at a displaydevice coupled to the processor. The method may further include,receiving, at the processor, an indication of second user input. Thesecond user input may correspond to a transmit-message functionality ofthe data communications software. The method may yet further includetransforming, by the processor, the private data, to create transformedprivate data. The method may still yet further include outputting, bythe processor, the transformed private data, to the GUI of the datacommunications software. The method may also include, responsive toreceiving the indication of the second user input, initiating, by theprocessor, transmission of the transformed private data by the datacommunications software.

According to an example implementation, another method is provided. Themethod may include presenting, over a textual communications app GUIbeing displayed by the mobile computing device, an overlay GUI. Theoverlay GUI may comprise at least one user interface element overlayinga portion of the textual communications app GUI for receiving textualdata. The method may further include, receiving, at the at least oneprocessor, plaintext data corresponding to first user input received atthe mobile computing device. The textual data may be formatted for entryinto the portion of the textual communications app GUI for receivingtextual data. The method may yet further include encrypting, by the atleast one processor, the plaintext data, to create ciphertext data. Themethod may still yet further include receiving, at the at least oneprocessor, an indication of second user input received at the mobilecomputing device. The second user input may correspond to atransmit-message functionality of the textual communications app. Themethod may also include directing, by the at least one processor, theciphertext data, to the GUI of the textual communications app. Themethod may further include, responsive to receiving the indication ofthe second user input, initiating, by the processor, transmission of afirst message including the ciphertext data by the textualcommunications app

According to another example implementation, a computer program productis provided. The computer program product may be embodied in anon-transitory computer-readable medium, and may store instructionsthat, when executed by at least one processor, causes the at least oneprocessor to perform a method substantially similar the above-describedmethods.

According to another example implementation, a system is provided. Thesystem may include at least one memory operatively coupled to at leastone processor and configured for storing data and instructions that,when executed by the at least one processor, cause the system to performa method substantially similar the above-described methods.

Other implementations, features, and aspects of the disclosed technologyare described in detail herein and are considered a part of the claimeddisclosed technology. Other implementations, features, and aspects canbe understood with reference to the following detailed description,accompanying drawings, and claims.

BRIEF DESCRIPTION OF THE FIGURES

Reference will now be made to the accompanying figures and flowdiagrams, which are not necessarily drawn to scale, and wherein:

FIG. 1 depicts a block diagram of illustrative computing devicearchitecture 100, according to an example implementation.

FIG. 2 depicts a flow diagram of a transformation 200 of plaintext tociphertext, according to an example implementation.

FIG. 3 depicts an illustration of an email app interface when the systemis active 300A, and when the system is inactive 300B, respectively,according to an example implementation.

FIG. 4 depicts an illustration of an email app interface 400 with mimicGUIs 401A 401B indicated in different colors.

FIG. 5 depicts an illustration of a password prompt interface 500,according to an example implementation.

FIG. 6 depicts an illustration of the UI Automator Viewer interface 600,according to an example implementation.

FIG. 7 depicts a flow diagram of a method 700, according to an exampleimplementation.

FIG. 8 depicts a flow diagram of another n method 800, according to anexample implementation.

DETAILED DESCRIPTION

Users are increasingly storing, accessing, and exchanging data throughpublic cloud services (PCS). Although many users rely on cloud providersto provide sufficient security protection, the confidentiality of datain public clouds may be violated by third parties, or PCS providersthemselves. Consequently, PCS should not be trusted to ensure dataprivacy.

Implementations of the disclosed technology include novel techniques forimproving data privacy in mobile communications over public cloudservices. According to certain implementations, a new conceptual layermay be interposed between the “application” layer and the “user” layer.In some implementations, the conceptual layer may be at least partiallyembodied by a transparent window or pane overlaid on top of existing appgraphical user interfaces (GUIs) to: (1) intercept plaintext user inputbefore transforming the input and feeding it to an underlying app; and(2) reverse transform output data from the app before displaying theplaintext data to the user. Accordingly, the conceptual layer may serveas a protective layer while preserving the original application workflowand look-and-feel.

This approach may allow certain implementations to support trueend-to-end encryption of user data with three goals in mind: (1) dataand logic isolation from untrusted entities; (2) the preservation oforiginal user experience with target apps; and (3) applicability to alarge number of apps and resilience to app updates. Accordingly, someimplementations may transparently integrate with cloud services withouthindering usability and without the need to reverse engineer cloudservice client apps.

Throughout this disclosure, certain implementations are described inexemplary fashion in relation to safeguarding data communications acrosspublic cloud services accessed from mobile platforms. However,implementations of the disclosed technology are not so limited. In someimplementations, the disclosed technology may be effective in securingcommunications across private clouds and other services or networks, orsecuring communications sent from PC/desktop platforms. Moreover,certain implementations may be effective in securing the transmission ofmultimedia data, binaries, and other files in addition to text-basedcommunications (collectively referred to herein as “private data”).

Some implementations of the disclosed technology will be described morefully hereinafter with reference to the accompanying drawings. Thisdisclosed technology may, however, be embodied in many different formsand should not be construed as limited to the implementations set forththerein.

In the following description, numerous specific details are set forth.However, it is to be understood that implementations of the disclosedtechnology may be practiced without these specific details. In otherinstances, well-known methods, structures, and techniques have not beenshown in detail in order not to obscure an understanding of thisdescription. References to “one implementation,” “an implementation,”“example implementation,” “some implementations,” “certainimplementations,” “various implementations,” etc., indicate that theimplementation(s) of the disclosed technology so described may include aparticular feature, structure, or characteristic, but not everyimplementation necessarily includes the particular feature, structure,or characteristic. Further, repeated use of the phrase “in oneimplementation” does not necessarily refer to the same implementation,although it may.

Throughout the specification and the claims, the following terms take atleast the meanings explicitly associated herein, unless the contextclearly dictates otherwise. The term “or” is intended to mean aninclusive “or.” Further, the terms “a,” “an,” and “the” are intended tomean one or more unless specified otherwise or clear from the context tobe directed to a singular form.

Unless otherwise specified, the use of the ordinal adjectives “first,”“second,” “third,” etc., to describe a common object, merely indicatethat different instances of like objects are being referred to, and arenot intended to imply that the objects so described should be in a givensequence, either temporally, spatially, in ranking, or in any othermanner.

In some instances, a computing device may be referred to as a mobiledevice, mobile computing device, a mobile station (MS), terminal,cellular phone, cellular handset, personal digital assistant (PDA),smartphone, wireless phone, organizer, handheld computer, desktopcomputer, laptop computer, tablet computer, set-top box, television,appliance, game device, medical device, display device, or some otherlike terminology. In other instances, a computing device may be aprocessor, controller, or a central processing unit (CPU). In yet otherinstances, a computing device may be a set of hardware components.

A presence-sensitive input device as discussed herein, may be a devicethat accepts input by the proximity of a finger, a stylus, or an objectnear the device. A presence-sensitive input device may also be a radioreceiver (for example, a Wi-Fi receiver) and processor which is able toinfer proximity changes via measurements of signal strength, signalfrequency shifts, signal to noise ratio, data error rates, and otherchanges in signal characteristics. A presence-sensitive input device mayalso detect changes in an electric, magnetic, or gravity field.

A presence-sensitive input device may be combined with a display toprovide a presence-sensitive display. For example, a user may provide aninput to a computing device by touching the surface of apresence-sensitive display using a finger. In another exampleimplementation, a user may provide input to a computing device bygesturing without physically touching any object. For example, a gesturemay be received via a video camera or depth camera.

In some instances, a presence-sensitive display may have two mainattributes. First, it may enable a user to interact directly with whatis displayed, rather than indirectly via a pointer controlled by a mouseor touchpad. Secondly, it may allow a user to interact without requiringany intermediate device that would need to be held in the hand. Suchdisplays may be attached to computers, or to networks as terminals. Suchdisplays may also play a prominent role in the design of digitalappliances such as a PDA, satellite navigation devices, mobile phones,and video games. Further, such displays may include a capture device anda display.

Various aspects described herein may be implemented using standardprogramming or engineering techniques to produce software, firmware,hardware, or any combination thereof to control a computing device toimplement the disclosed subject matter. A computer-readable medium mayinclude, for example: a magnetic storage device such as a hard disk, afloppy disk or a magnetic strip; an optical storage device such as acompact disk (CD) or digital versatile disk (DVD); a smart card; and aflash memory device such as a card, stick or key drive, or embeddedcomponent. Additionally, it should be appreciated that a carrier wavemay be employed to carry computer-readable electronic data includingthose used in transmitting and receiving electronic data such aselectronic mail (e-mail) or in accessing a computer network such as theInternet or a local area network (LAN). Of course, a person of ordinaryskill in the art will recognize many modifications may be made to thisconfiguration without departing from the scope or spirit of the claimedsubject matter.

Various systems, methods, and computer-readable mediums are disclosedfor improving data privacy in mobile communications over public cloudservices, and will now be described with reference to the accompanyingfigures.

FIG. 1 depicts a block diagram of illustrative computing devicearchitecture 100, according to an example implementation. Certainaspects of FIG. 1 may be embodied in a computing device 200 (forexample, a mobile computing device). As desired, implementations of thedisclosed technology may include a computing device with more or less ofthe components illustrated in FIG. 1. It will be understood that thecomputing device architecture 100 is provided for example purposes onlyand does not limit the scope of the various implementations of thepresent disclosed systems, methods, and computer-readable mediums.

The computing device architecture 100 of FIG. 1 includes a CPU 102,where computer instructions are processed; a display interface 104 thatacts as a communication interface and provides functions for renderingvideo, graphics, images, and texts on the display. In certainimplementations of the disclosed technology, the display interface 104may be directly connected to a local display, such as a touch-screendisplay associated with a mobile computing device. In another exampleimplementation, the display interface 104 may be configured forproviding data, images, and other information for an external/remotedisplay that is not necessarily physically connected to the mobilecomputing device. For example, a desktop monitor may be utilized forminoring graphics and other information that is presented on a mobilecomputing device. In certain some implementations, the display interface104 may wirelessly communicate, for example, via a Wi-Fi channel orother available network connection interface 112 to the external/remotedisplay.

In an example implementation, the network connection interface 112 maybe configured as a communication interface and may provide functions forrendering video, graphics, images, text, other information, or anycombination thereof on the display. In one example, a communicationinterface may include a serial port, a parallel port, a general purposeinput and output (GPIO) port, a game port, a universal serial bus (USB),a micro-USB port, a high definition multimedia (HDMI) port, a videoport, an audio port, a Bluetooth port, a near-field communication (NFC)port, another like communication interface, or any combination thereof.

The computing device architecture 100 may include a keyboard interface106 that provides a communication interface to a keyboard. In oneexample implementation, the computing device architecture 100 mayinclude a presence-sensitive display interface 107 for connecting to apresence-sensitive display. According to certain some implementations ofthe disclosed technology, the presence-sensitive display interface 107may provide a communication interface to various devices such as apointing device, a touch screen, a depth camera, etc. which may or maynot be associated with a display.

The computing device architecture 100 may be configured to use an inputdevice via one or more of input/output interfaces (for example, thekeyboard interface 106, the display interface 104, the presencesensitive display interface 107, network connection interface 112,camera interface 114, sound interface 116, etc.) to allow a user tocapture information into the computing device architecture 100. Theinput device may include a mouse, a trackball, a directional pad, atrack pad, a touch-verified track pad, a presence-sensitive track pad, apresence-sensitive display, a scroll wheel, a digital camera, a digitalvideo camera, a web camera, a microphone, a sensor, a smartcard, and thelike. Additionally, the input device may be integrated with thecomputing device architecture 100 or may be a separate device. Forexample, the input device may be an accelerometer, a magnetometer, adigital camera, a microphone, and an optical sensor.

Example implementations of the computing device architecture 100 mayinclude an antenna interface 110 that provides a communication interfaceto an antenna; a network connection interface 112 that provides acommunication interface to a network. In certain implementations, acamera interface 114 is provided that acts as a communication interfaceand provides functions for capturing digital images from a camera. Incertain implementations, a sound interface 116 is provided as acommunication interface for converting sound into electrical signalsusing a microphone and for converting electrical signals into soundusing a speaker. According to example implementations, a random accessmemory (RAM) 118 is provided, where computer instructions and data maybe stored in a volatile memory device for processing by the CPU 102.

According to an example implementation, the computing devicearchitecture 100 includes a read-only memory (ROM) 120 where invariantlow-level system code or data for basic system functions such as basicinput and output (I/O), startup, or reception of keystrokes from akeyboard are stored in a non-volatile memory device. According to anexample implementation, the computing device architecture 100 includes astorage medium 122 or other suitable type of memory (e.g., RAM, ROM,programmable read-only memory (PROM), erasable programmable read-onlymemory (EPROM), electrically erasable programmable read-only memory(EEPROM), magnetic disks, optical disks, floppy disks, hard disks,removable cartridges, flash drives), where the files include anoperating system (OS) 124, application programs 126 (including, forexample, a web browser application, a widget or gadget engine, and orother applications, as necessary) and data files 128 are stored.According to an example implementation, the computing devicearchitecture 100 includes a power source 130 that provides anappropriate alternating current (AC) or direct current (DC) to powercomponents. According to an example implementation, the computing devicearchitecture 100 includes a telephony subsystem 132 that allows thedevice 100 to transmit and receive sound over a telephone network. Theconstituent devices and the CPU 102 communicate with each other over abus 134.

According to an example implementation, the CPU 102 has appropriatestructure to be a computer processor. In one arrangement, the CPU 102may include more than one processing unit. The RAM 118 interfaces withthe computer bus 134 to provide quick RAM storage to the CPU 102 duringthe execution of software programs such as the operating systemapplication programs, and device drivers. More specifically, the CPU 102loads computer-executable process steps from the storage medium 122 orother media into a field of the RAM 118 in order to execute softwareprograms. Data may be stored in the RAM 118, where the data may beaccessed by the computer CPU 102 during execution. In one exampleconfiguration, the device architecture 100 includes at least 125 MB ofRAM, and 256 MB of flash memory.

The storage medium 122 itself may include a number of physical driveunits, such as a redundant array of independent disks (RAID), a floppydisk drive, a flash memory, a USB flash drive, an external hard diskdrive, thumb drive, pen drive, key drive, a High-Density DigitalVersatile Disc (HD-DVD) optical disc drive, an internal hard disk drive,a Blu-Ray optical disc drive, or a Holographic Digital Data Storage(HDDS) optical disc drive, an external mini-dual in-line memory module(DIMM) synchronous dynamic random access memory (SDRAM), or an externalmicro-DIMM SDRAM. Such computer readable storage media allow a computingdevice to access computer-executable process steps, application programsand the like, stored on removable and non-removable memory media, tooff-load data from the device or to upload data onto the device. Acomputer program product, such as one utilizing a communication systemmay be tangibly embodied in storage medium 122, which may comprise amachine-readable storage medium.

According to one example implementation, the term computing device, asused herein, may be a CPU, or conceptualized as a CPU (for example, theCPU 102 of FIG. 1). In this example implementation, the computing devicemay be coupled, connected, and/or in communication with one or moreperipheral devices, such as display. In another example implementation,the term computing device, as used herein, may refer to a mobilecomputing device, such as a smartphone or tablet computer. In thisexample implementation, the computing device may output content to itslocal display and/or speaker(s). In another example implementation, thecomputing device may output content to an external display device (e.g.,over Wi-Fi) such as a TV or an external computing system.

In some implementations of the disclosed technology, the computingdevice may include any number of hardware and/or software applicationsthat are executed to facilitate any of the operations. In someimplementations, one or more I/O interfaces may facilitate communicationbetween the computing device and one or more input/output devices. Forexample, a universal serial bus port, a serial port, a disk drive, aCD-ROM drive, and/or one or more user interface devices, such as adisplay, keyboard, keypad, mouse, control panel, touch screen display,microphone, etc., may facilitate user interaction with the computingdevice. The one or more I/O interfaces may be utilized to receive orcollect data and/or user instructions from a wide variety of inputdevices. Received data may be processed by one or more computerprocessors as desired in various implementations of the disclosedtechnology and/or stored in one or more memory devices.

One or more network interfaces may facilitate connection of thecomputing device inputs and outputs to one or more suitable networksand/or connections; for example, the connections that facilitatecommunication with any number of sensors associated with the system. Theone or more network interfaces may further facilitate connection to oneor more suitable networks; for example, a local area network, a widearea network, the Internet, a cellular network, a radio frequencynetwork, a Bluetooth enabled network, a Wi-Fi® enabled network, asatellite-based network any wired network, any wireless network, etc.,for communication with external devices and/or systems, for example, viapublic cloud service.

INTRODUCTION

Many of the most popular mobile apps available today are communicationsapps facilitating text-based end-to-end communication services such asemail, instant/IP messaging via various PCS providers. In an analogousfashion to mail carriers delivering letters, PCS providers may beconsidered content-agnostic message routers. That is, PCS providers mayfunction normally without needing to know the content of the messagesbeing delivered. Thus, users should be able to enjoy the same quality ofservice without needing to reveal their plaintext data to PCS providers.Thus, applying end-to-end encryption (E2EE) without assuming trust inthe PCS providers would appear to mitigate vulnerabilities in PCSnetworks.

In practice, however, the direct application of E2EE solutions in themobile device environment has proven challenging. A good solution shouldpresent clear advantages to the entire mobile security ecosystem. Inparticular, a robust solution should account for at least these factors:(1) the ease-of-use of the solution, and its corresponding effects onacceptability and adoptability; (2) the developers' efforts to maintainsupport for the solution, especially with a rapidly changing softwareecosystem; and (3) the feasibility and deployability of the solution ona mobile system. In view of these factors, three design goals wereformulated:

1. For a solution to be secure, it should be properly isolated fromuntrusted entities. E2EE cannot guarantee data confidentiality ifplaintext data or an encryption key can be compromised through anarchitecture that risks exposing these values. Traditional solutionslike PGP® and even more recent efforts like Gibberbot, TextSecure, andSafeSlinger may provide acceptable isolation, but force users to usecustom apps (and corresponding UI and workflows), which may hinderadoption and cause usability problems.

Solutions that repackage or rewrite existing apps to introduceadditional security checks or solutions in the form of browserplugins/extensions may avoid or mitigate these issues. However,conventional browser plugins/extensions generally do not fit into themobile security landscape because many mobile browsers do not supportextensions, and mobile device users do not favor using mobile browsersto access PCS. Thus, browser plugin/extension-based solutions are likelyinsufficient to meet the formulated goals.

2. For a solution to be adoptable, it should preserve the original userexperience. Research suggests that users will not accept solutions thatrequire them to switch between multiple apps to perform their dailytasks. Therefore, simply porting solutions like PGP to a mobile platformwould not be effective, as PGP forces users to use a separate and customapp, and it would be infeasible to recreate the richness and unique userexperience of all existing text routing apps offered by various PCSproviders today. In the context of mobile devices, PCS are competing formarket share not only based on functionality and reliability, but alsouser experience. Ultimately, many users will choose apps that feel themost comfortable. To reduce interference with a user's interaction withthe app of their choice, security solutions should be capable ofretrofit to existing apps. Solutions that repackage/rewrite existingapps may meet this criterion.

3. For a solution to be sustainable, it should be easy to maintain andscalable. The solution should be sufficiently general-purpose, requireminimal effort to support new apps, and withstand at least minor appupdates, if not full version changes.

In the past, email was one a few viable means of electroniccommunication. Protecting email communications should be relativelystraightforward because email protocols (e.g., POP and IMAP) are welldefined. Custom privacy-preserving apps may therefore, in theory, bebuilt to serve this need. However, with the introduction of PCS and newvaried forms of electronic communications, a good solution should alsobe able to integrate security features into apps without requiringreverse engineering of the apps' logic or network protocols, which maybe undocumented or proprietary (see Skype™ or WhatsApp®, for example).

As described herein, implementations of the disclosed technology includetechniques for improving data privacy in mobile communications overpublic cloud services (PCS). According to certain implementations, aprivacy-preserving system, referred to herein as “M-Ageis,” may mimicthe look and feel of existing apps to preserve their user experience andworkflow on mobile devices, without changing the underlying OS ormodifying/repackaging existing apps.

Certain implementations of the disclosed technology may meet all or someof the above-described goals by operating at a conceptual layer referredto herein as “Layer 7.5” (also “L-7.5” or “7.5”). In someimplementations, Layer 7.5 may operate above the existing applicationlayer (e.g., OSI Layer 7), and interact directly with the user(popularly labeled as Layer 8).

From a system's perspective, L-7.5 may include a transparent window orpane in an isolated process that interposes itself between Layer 7 andLayer 8. The interconnectivity between these layers may be achievedusing the accessibility framework, an essential feature on many modernoperating systems. In some implementations, L-7.5 may extract the GUIinformation of an app below it through the OS's user interfaceautomation/accessibility (UIA) library. In other implementations, it mayextract the UI information directly from the operating system (OS).

Using this information, an example implementation may be able to proxyuser input by rendering its own overlay GUI and subsequently handle userinput, for example, to process plaintext data or intercept a user'sbutton click. In some implementations, the overlay GUI may be indicatedwith a different color, or other visual cue, to let the user know thesystem is running.

L-7.5 may also programmatically interact with various UI components ofthe app below on behalf of the user, as described herein. Since manymajor software vendors today have pledged their commitment towardscontinuous support and enhancement of accessibility interface fordevelopers, this UIA-based technique (or, the OS-based technique) islikely to remain applicable and sustainable on all major platforms.

From a security design perspective, certain implementations may supporttwo privacy objectives during a user's interaction with a target app:(1) all input from the user may go first to L-7.5 (and be optionallyprocessed) before being passed to an app. This means that confidentialdata and user intent may be fully captured; and (2) all output from theapp may go through L-7.5 (and is optionally processed) before beingdisplayed or otherwise presented to the user.

From a developer's perspective, according to certain implementations,accessing and interacting with a target app's UI components at L-7.5 maybe similar to that of manipulating the DOM tree of a web app usingJavaScript. While DOM tree manipulation only works for browsers, UIA andOS UI support may work for all apps on a platform. To track the GUI ofan app, some implementations may rely on resource ID names availablethrough the UIA library. Other implementation may rely on informationextracted from the OS.

Therefore, certain implementations may be resilient to updates thatchange the look and feel of the app (e.g. position, color, sizing, etc.of UI elements). Some implementations only requires resource ID names toremain the same, which, through empirical evidence, often holds trueeven through significant version changes. Even if a resource ID changes,minimal effort may be required to rediscover resource ID names and remapthem to the corresponding logic. Accordingly, some implementations willnot require developer update to continue normal function after updatesto the target app.

From a user's perspective, according to certain implementations, thecustom GUI may be visible as an always-on-top button or other widget.When it is turned on, users may perceive that they are interacting withthe original app in plaintext mode. A lone noticeable difference may bethat the GUI of the original app may appear in a different color toindicate that protection is activated. This means that subtle featuresthat contribute towards the entire user experience such as spellchecking and in-app navigation may be preserved. Despite userperception, however, the underlying app may never actually receiveplaintext data.

FIG. 2 depicts a flow diagram of a transformation 200 of plaintext tociphertext, according to an example implementation. In FIG. 2, M-Aegisuses L-7.5 to transparently reverse-transform the message “deadbeef”into “Hi there.” The system may also allow a user to enter theirplaintext message “Hello world” into M-Aegis's text box. To the user,the overlay GUI may look exactly or near-exactly like the original app.When the user decides to send a message, the “Hello world” message maybe transformed and relayed to the underlying app.

Threat Model and Architecture

According to certain implementations, there are three parties that maypose a threat to the confidentiality of users' data exposed to publiccloud through mobile devices. Therefore, these parties are assumed to beuntrustworthy in the corresponding threat model:

1. Public cloud service (PCS) providers. Sensitive data stored in thepublic cloud may be compromised in several ways. For example, (a) PCSproviders maybe compelled by law to provide access to a user's sensitivedata to law enforcement agencies; (b) the business model of PCSproviders creates strong incentive for them to share/sell user data withthird parties; (c) PCS administrators who have access to the sensitivedata may compromise the data, either intentionally, or byaccident/negligence; and (d) vulnerabilities of the PCS are exploitableby attackers to exfiltrate sensitive data.

2. Client-side apps. Since client-side apps are often provided by PCSproviders to allow a user to access their services, it follows thatthese apps also may be considered untrustworthy.

3. Middle boxes between a PCS and a client-side app. Sensitive data mayalso be compromised when it is transferred between a PCS and aclient-side app. Incorrect protocol design/implementation may allowattackers to eavesdrop on plaintext data or perform Man-in-the-Middleattacks.

Certain implementations may mitigate or avoid some or all of the abovethreats by using L-7.5 to facilitate end-to-end encryption (E2EE) foruser private data. In some implementations, the following components mayform, or be included in, the trusted computing base (TCB): the hardware(see, e.g., FIG. 1), the OS 124, and the framework that controls andmediates access to hardware. In the absence of physical input devices(e.g., mouse and keyboard), the soft keyboard may be additionallytrusted to not leak the keystrokes of a user. The TCB is relied upon tocorrectly handle I/O, and to provide proper isolation between M-Aegisand untrusted components. In some implementations, it is further assumedthat all the components of the system, including the L-7.5 that itcreates, are trusted. Finally, the user may be considered trusted in hisintent. This means that the user may be trusted to turn on or activateimplementations of the disclosed technology when he wants to protect theprivacy of his data during his interaction with PCS.

Certain implementations are architected to fulfill some or all of thedesign goals described hereinabove. To achieve a strong isolation, someimplementations may execute in a separate process although residing inthe same OS as the target client app (TCA). Besides memory isolation,the file system may be also shielded from other apps by OS app sandboxprotection. Should a greater degree of isolation be desirable, anunderlying virtual-machine-based system may be adopted to provide evenstronger security guarantees.

According to certain implementations, some of the main components thatmake up M-Aegis include:

Layer 7.5 (L-7.5). Certain implementations may interpose a novelconceptual layer called Layer 7.5 between the user and the TCA. This mayallow the introduction of true end-to end encryption (E2EE) withoutexposing plaintext data to the TCA, and all while maintaining the TCA'soriginal functionalities and user experience, according to the seconddesign goal. L-7.5 may be implemented by creating a transparent windowthat is always on top of the UI (or maintains UI focus). This techniquemay be advantageous in that it provides a natural way to handle userinteraction, thus preserving user experience without the need to reverseengineer the logic of TCAs or the network protocols used by the TCAs tocommunicate with their respective cloud service back-ends, fulfillingthe third design goal.

According to certain implementations, there may be three cases of userinteractions to handle. The first case includes interactions that do notinvolve data confidentiality, such as deleting or relabeling email. Suchinput may not require extra processing or transformation, and may bedirectly delivered to the underlying TCA. Such click-through behavior isa natural property of transparent windows, and helps the system maintainthe look and feel of the TCA.

The second case considers interactions that involve dataconfidentiality, such as entering messages or searching encrypted email.Such input may require extra processing (e.g., encryption and encodingoperations). For such cases, the system may place overlay GUIs that“mimic” the app GUIs over the TCA, which are purposely painted indifferent colors for two reasons: (1) as a placeholder for user input sothat it does not leak to the TCA, and (2) for user visual feedback.Mimic GUIs for the subject 401A and content 401B as seen in FIG. 4 aresuch examples. Since L-7.5 is always on top, this may provide a strongguarantee that user input will always go to a mimic GUI instead of theTCA.

The third case considers interactions with control GUIs (e.g., sendmessage buttons). Such input may require user action to be “buffered”while the input from the second case is being processed, before beingrelayed to the actual control GUI of the TCA. For such cases, the systemmay create semi-transparent mimic GUIs that register themselves toabsorb/handle user clicks/taps. Again, these mimic GUIs may be paintedwith a different color to provide a visual cue to a user. Examples ofthese include the purple search button 305 in the left figure in FIG. 3and the purple send button 405 in FIG. 4.

UI Manager (UIM). According to certain implementations, there arecertain capabilities the system may require to be fully functional thatare not commonly available to normal apps. First, although the systemmay be confined within the OS' app sandbox, it should be able todetermine with which TCA the user is currently interacting. This allowsthe system to invoke specific logic to handle the TCA, and helps thesystem clean up the screen when the TCA is terminated. Second, thesystem may require information about the GUI layout for the TCA it iscurrently handling. This allows the system to properly render mimic GUIson L-7.5 to intercept user I/O. Third, although isolated from the TCA,the system should be able to communicate with the TCA to maintainfunctionality and ensure user experience is not disrupted. For example,the system should be able to relay user clicks (or other gestures orinput events) to the TCA, eventually send encrypted data to the TCA, andclick or otherwise interact with the TCA's button or widget on behalf ofthe user. For output on screen, the system should be able to captureciphertext so that it can decrypt it and then render it on L-7.5.

In some implementations, the system may extract certain features fromthe underlying OS's accessibility framework, which may be exposed todevelopers in the form of the User Interface Accessibility/Automation(UTA) library, or from the OS directly without the help of the UTAlibrary. Using UTA or direct OS support, the system may be not only ableto know which TCA is currently executing, but may query the GUI tree ofthe TCA to get detailed information about how the page is laid out(e.g., location, size, type, and resource ID of the GUI components).More importantly, the system may be able to obtain information about thecontent of these GUI items.

Exploiting UIA or OS support may be advantageous to this design ascompared to other methods of information capture from the GUI such asoptical character recognition (OCR). However, such methods may be usedalternatively, or in conjunction with UIA or OS probing in certainimplementations. In addition to having virtually perfect content captureaccuracy, the UIA-based or OS-based techniques are not limited by screensize. For example, FIG. 3 depicts an illustration of an email appinterface when the system is active 300A, and when the system isinactive 300B, respectively, according to an example implementation.Even though the screen size may prevent the full text from beingdisplayed, M-Aegis is still able to capture text in its entirety throughthe UIA libraries or OS support, permitting the system to applydecryption to ciphertext. These capabilities and advantages were used tobuild a crucial component of system called the UI manager (UIM).

Per-TCA Logic

According to certain implementations, the system may be extended tosupport many TCAs. For each TCA of interest, per-TCA logic may be builtas an extension module. The per-TCA logic may be responsible forrendering the specific mimic GUIs according to information it queriesfrom the UIM. Therefore, per-TCA logic may be responsible for handlingdirect user input. Specifically, the logic may decide whether the userinput will be directly passed to the TCA or be encrypted and encodedbefore doing so. This may ensure that the TCA does not obtain plaintextdata while user interaction is in plaintext mode. Per-TCA logic may alsointercept button clicks so that it may then instruct UIM to emulate theuser's action on the button in the underlying TCA. Per-TCA logic mayalso decide which encryption and encoding scheme to use according to thetype of TCA it is handling. For example, encryption and encoding schemesfor handling email apps may differ from that of messenger apps.

Cryptographic Module. According to certain implementations, the system'scryptographic module may be responsible for providingencryption/decryption and cryptographic hash capabilities to support thesearchable encryption scheme to the per-TCA logic, thereby enabling thesystem to transform/obfuscate messages through E2EE operations. Besidesstandard cryptographic primitives, this module may also include asearchable encryption scheme to support search over encrypted email thatworks without server modification. Since the discussion of anyencryption scheme is not complete without encryption keys, the keymanager may also be a part of this module.

Key Manager. In some implementations, the system may have a key managerper TCA that manages key policies that may be specific to each TCAaccording to user preference. The key manager may support a range ofschemes, including simple password-based key derivation functions (whichmay be shared out of band) to derive symmetric keys, to moresophisticated PKI-based schemes for users who prefer stronger securityguarantees and do not mind the additional key set-up and exchangeoverheads. Techniques for key management/distribution are known in theart and not discussed at length herein.

Searchable Encryption Scheme (EDESE). Numerous conventional encryptionschemes support keyword search. These schemes exhibit differenttradeoffs between security, functionality and efficiency, but all ofthem require modifications on the server side. Since server cooperationmay not be assumed, a new searchable encryption scheme was designedcalled easily deployable efficiently-searchable symmetric encryptionscheme (EDESE). EDESE is an adaptation of a scheme proposed by Bellareet al. with modifications similar to that of Goh's scheme, and isretrofittable to a non-modifying server scenario.

In some implementations, EDESE may be incorporated for emailapplications. The idea for the construction is simple: the document isencrypted with a standard encryption scheme and HMACs appended of uniquekeywords in the document. To prevent leaking the number of uniquekeywords, as many “dummy” keywords are added as needed.

According to certain implementations, in order to achieve higher storageand search efficiency, a Bloom filter (BF) may be used to represent theEDESE index. Basically, a BF is a data structure that allows forefficient set-inclusion tests. However, such set-inclusion tests basedon BFs are currently not supported by existing email providers, whichonly support string-based searches. Therefore, a solution was devisedthat encodes the positions of on-bits in a BF as Unicode strings.

When the underlying data structure that is used to support EDESE is aBF, search operations may be susceptible to false positives matches.However, this does not pose a real problem to users, because the falsepositive rate may be extremely low and is completely adjustable. In oneimplementation, the parameters are as follows: the length of keyword (inbits) is estimated to be k=128, the size of the BF array is B=2²⁴, themaximum number of unique keywords used in any email thread is estimatedto be d=10⁶, the number of bits set to 1 for one keyword is r=10.Plugging these values into the formula for false positive calculation,i.e., (1−e^(−rd/B))^(r) the probability of a false positive δ may becapped to 0.0003.

User Workflow

The following workflow illustrates operation of an exampleimplementation of the system for a user composing and sending an emailusing the stock Gmail™ app on Android™.

1. When the user launches the Gmail™ app, the UIM notifies the correctper-TCA logic of the event. The per-TCA logic will then initializeitself to handle the Gmail™ workflow.

2. Responsive to Gmail™ being launched, the per-TCA logic will try todetect the state of Gmail app (e.g., preview, reading, or composingemail). This allows M-Aegis to properly create mimic GUIs on L-7.5 tohandle user interaction. For example, when a user is on the composepage, the per-TCA logic will mimic the GUIs of the subject and contentfields, as seen in FIG. 4, 401A-B. The user then interacts directly withthese mimic GUIs in plaintext mode without extra effort. Thus, theworkflow is unmolested. Note that essential but subtle features likespell check and autocorrect are still preserved, as they may be innatefeatures of the mobile device's soft keyboard. Additionally, the “send”button is also mimicked to capture user intent.

(3) As the user finishes composing his email, he clicks on the mimicked“send” button on L-7.5. Since L-7.5 receives the user input and not theunderlying Gmail app, the per-TCA logic is able to capture this eventand proceed to process the subject and the content.

(4) The per-TCA logic selects the appropriate encryption key to be usedbased on the recipient list and the predetermined key policy for Gmail™.If a key cannot be found for this conversation, M-Aegis prompts the user(as shown in FIG. 5) for a password to derive a new key. After obtainingthe associated key for this conversation, M-Aegis will then encryptthese inputs and encode it back to text such that Gmail™ can consume it.

(5) The per-TCA logic requests the UIM to fill in the corresponding GUIson Gmail™ with the transformed text. After they are filled, the UIM isinstructed to click the actual “send” button on behalf of the user. Thisprovides a transparent experience to the user.

From this example workflow, it should be evident that from the user'sperspective, the workflow of using Gmail™ remains the same, because ofthe mimicking properties of M-Aegis.

Example Implementation

An example of M-Aegis was implemented using Java® on Android™, as anaccessibility service. This was done by creating a class that extendsthe AccessibilityService class and requesting the BIND ACCESSIBILITYSERVICE permission in the manifest. This allowed interfacing with theUTA library, for building the UIM.

This example implementation of M-Aegis was deployed on two Androidphones from separate manufacturers, the Samsung Galaxy® Nexus™ and LG®Nexus™ 4, and targeted several versions of Android™ from Android™ 4.2.2(API level 17) to Android™ 4.4.2 (API level 19). The deployment was doneon stock devices and OS (i.e., without modifying the OS, Androidframework, or “rooting”). Only simple app installation was performed.This demonstrates the ease of deployment and distribution of thesolution. Another prototype was implemented on Windows® 7 to demonstrateinteroperability and generality of approach, but is not discuss atlength herein.

As an interface to the user, a button was created that is always on topeven if other apps are launched. This allowed the creation of anon-bypassable direct channel of communication with the user in additionto providing a visual cue of whether M-Aegis is turned on or off. Forapp support, Gmail™ was used as an example of an email app and WhatsApp®as an example of a messenger app.

Cryptographic Schemes. For encryption/decryption operations, AES-GCM-256was used. For a password-based key generation algorithm, PBKDF2 withSHA-1 was used as the keyed-hash message authentication code (HMAC).HMAC-SHA-256 was also used as the HMAC to generate tags for emailmessages. These functionalities are available in Java's javax.crypto andjava.security packages.

For the sake of usability, a password-based scheme was implemented asthe default, and one password was assumed for each group of messagerecipients. The users were relied upon to communicate the password tothe receiving parties using an out-of-band channel (e.g., in person orvia phone call). For messaging apps, an authenticated Diffie-Hellman keyexchange protocol was implemented to negotiate session keys forWhatsApp® conversations. A PGP key was automatically generated for auser during installation based on the hashed phone number, and wasdeposited to publicly accessible repositories on the user's behalf(e.g., MIT PGP Key Server). Since all session and private keys werestored locally for user convenience, it was ensured that they were neversaved to disk in plaintext. The keys were additionally encrypted with akey derived from a master password that is provided by the user duringinstallation.

UIM. As mentioned earlier, UIM may be implemented using UIA libraries ordirect OS support. On Android, events that signify something new beingdisplayed on the screen may be detected by monitoring following theevents: WINDOW CONTENT CHANGED, WINDOW STATE CHANGED, and VIEW SCROLLED.Upon receiving these events, per-TCA logic may be informed. The UIAlibrary may present a data structure in the form of a tree with nodesrepresenting UI components with the root being the top window. This mayallow the UIM to locate all UI components on the screen.

Additionally, Android's UIA framework also provides the ability to queryfor UI nodes by providing a resource ID. For instance, the node thatrepresents search button of Gmail™ can be found by querying forcom.google.android.gm:id/search. More importantly, there may be no needto guess the names of these resource IDs. Rather, tools can be used toview the tree, such as UI Automator Viewer, which comes with the defaultAndroid SDK. FIG. 6 depicts an illustration of the UI Automator Viewerinterface 600, according to an example implementation. The UI AutomatorViewer presents an easy to use interface to examine the UTA tree anddetermine the resource ID 601A associated with a GUI element of interest601B.

Once the node of interest is found, all the other information about theGUI represented by the node may be found. This may include the exactlocation and size of text boxes, buttons, and other widgets on thescreen.

The system may be able to programmatically interact with various GUIs ofa TCA using the function performAction( ). This may allow the system toclick on or otherwise interact with a TCA's button on the user's behalf.

L-7.5. Layer 7.5 was implemented on Android™ as specific types of systemwindows, which are always-on-top of other running apps. Android™ allowsthe creation of various types of system windows. Two system windows,TYPE SYSTEM OVERLAY and TYPE SYSTEM ERROR were the focus here. The firstsystem window is for display only and allows all tap/keyboard events togo to underlying apps. In contrast, the second type allows for userinteraction. Android allows the use of any View objects for either typeof window, and this was used to create the mimic GUIs, and set theirsize and location.

The mimic GUIs were intentionally created in different colors as asubtle visual cue to the users that they are interacting with M-Aegis,without distracting them from their original workflow.

Per-TCA Logic. The general procedure for development of TCA logic was asfollows:

(1) Understand what the app does. This knowledge allows identificationof which GUIs need to be mimicked for intercepting user I/O. Fortext-based TCAs, this may be a trivial step because the corefunctionalities that M-Aegis needs to handle are limited and thus easyto identify, e.g. buffering user's typed texts and sending them to theintended recipient.

(2) Using UI Automator Viewer, examine the UTA tree for the relevantGUIs of a TCA and identify signatures (GUI resource IDs) for each TCAstate. UI Automator Viewer allows inspection of the UTA tree through agraphical interface (as shown in FIG. 6), which reduces developmenttime. UI components may be relied upon that are unique to certain states(e.g., the “send” button signifies presence in the compose state).

(3) For each relevant GUI, algorithms are devised to extract either thelocation or content of ciphertext (for decryption and display), or thetype, size, and location of GUIs that need to be mimicked (e.g., thesubject and content boxes in the Gmail™ compose UI). Again, this may beperformed through UI Automator Viewer. For example, for the Gmail™preview state, the UIA may be queried for nodes with IDcom.google.android.gm:/id/conversation list to identify all the UIAnodes corresponding to the preview item of each individual email, andfrom those all ciphertext may be extracted on the preview window throughthe UIA.

(4) Create event handlers for controls mimicked on L-7.5. For the Gmail™compose state, click/touch events are listened for on the L-7.5 “send”button, the email encryption process described herein is performed, andthe ciphertext is sent to the underlying TCA.

(5) Identify ways that each relevant state can be updated. Updates maybe handled via the following method: clear L-7.5, extract all necessaryinformation from the new state, and render again. This may be equivalentto redrawing all GUIs on L-7.5 based on the detected state.

There are least two details worth considering when developing per-TCAlogic. First, careful consideration should be given about the type ofinput data fed to TCAs. Since most TCAs only accept input data inspecific formats (e.g., text), they do not support the input of randombyte sequences as valid data. Therefore, encrypted data should beencoded into text format before feeding it as input to a TCA.Conventionally, base64 encoding is used for this purpose. However,base64 encoding may consume too much on-screen real estate. To overcomethis, the binary encrypted data was encoded into Chinese Japanese Korean(CJK) Unicode characters, which have efficient on-screen real estateconsumption. To map the binary data into the CJK plane, the encrypteddata may be processed at the byte granularity. For each byte, its valueis added to the base of the CJK Unicode representation, i.e., 0x4E00.For example, byte 0x00 may be encoded as “

”, and byte 0x01 will be represented as “

”.

Second, the system should be able to differentiate between ordinarymessages and encrypted messages. Markers were introduced into theencrypted data after encoding; in particular, the subject and contentsof a message were wrapped using a pair of curly braces (i.e., “{”, . . ., “}”).

Email Apps. In this subsection and the next, implementation detailsspecific to the email and messenger classes of apps are respectivelydescribed, including the message format created for each class.

Support for Gmail™ was implemented on the prototype as a representativeapp of email category. Two custom formats were created to communicatethe necessary metadata to support M-Aegis' functionalities:

Subject: {Encode(ID_(Key)∥IV∥Encrypt(Subject))}

Content: {Encode(Encrypt(Content)∥Tags)}

Once challenge faced in supporting decryption during the Gmail™ previewstate is that only the beginning parts of both the title and the subjectof each message may be available. Also, the exact email addresses of thesender and recipients are not always available, as some are displayed asaliases, and some are hidden due to lack of space. The lack of suchinformation makes it difficult to automatically decrypt the message evenif the corresponding encryption key actually exists on the system.

To address these problems, when a message is encrypted, a key-ID (IDKey)was included in the subject field (as seen in the format descriptionabove). Note that since the key-ID is not a secret, it need notnecessarily be encrypted. This way, all the needed information ispresent to decrypt correctly the subtext displayed on the Gmail™preview.

The Tags field was a collection of HMAC digests that are computed usingthe conversation key and keywords that exist in a particular email. Itwas then encoded and appended as part of the content that Gmail™receives to facilitate encrypted search without requiring modificationto Gmail™ servers.

Messenger Apps. Support for WhatsApp® was implemented on the prototypeas a representative app of this category. The format created for thisclass of apps was simple, as seen below:

Message: {Encode(IV∥Encrypt(Message))}

Example Methods

FIG. 7 depicts a flow diagram of a method 700, according to an exampleimplementation. As shown in FIG. 7, the method 700 starts in block 702,and, according to an example implementation, includes receiving, at aprocessor, private data corresponding to first user input at an inputdevice operatively coupled to the processor, wherein the private data isformatted for entry into a GUI of a data communications software, theGUI being displayed at a display device coupled to the processor. Inblock 704, the method 700 includes receiving, at the processor, anindication of second user input corresponding to a transmit-messagefunctionality of the data communications software. In block 706, themethod 700 includes transforming, by the processor, the private data, tocreate transformed private data. In block 708, the method 700 includesoutputting, by the processor, the transformed private data, to the GUIof the data communications software. In block 710, the method 700includes, responsive to receiving the indication of the second userinput, initiating, by the processor, transmission of the transformedprivate data by the data communications software.

FIG. 8 depicts a flow diagram of another n method 800, according to anexample implementation. As shown in FIG. 8, the method 800 starts inblock 802, and, according to an example implementation, includespresenting, over a textual communications app GUI being displayed by themobile computing device, an overlay GUI comprising at least one userinterface element overlaying a portion of the textual communications appGUI for receiving textual data. In block 804, the method 800 includesreceiving, at the at least one processor, plaintext data correspondingto first user input received at the mobile computing device, wherein thetextual data is formatted for entry into the portion of the textualcommunications app GUI for receiving textual data. In block 806, themethod 800 includes encrypting, by the at least one processor, theplaintext data, to create ciphertext data. In block 808, the method 800includes receiving, at the at least one processor, an indication ofsecond user input received at the mobile computing device, the seconduser input corresponding to a transmit-message functionality of thetextual communications app. In block 810, the method 800 includesdirecting, by the at least one processor, the ciphertext data, to theGUI of the textual communications app. In block 812, the method 800includes, responsive to receiving the indication of the second userinput, initiating, by the processor, transmission of a first messageincluding the ciphertext data by the textual communications app.

It will be understood that the various steps shown in FIGS. 7-8 areillustrative only, and that steps may be removed, other steps may beused, or the order of steps may be modified.

Certain implementations of the disclosed technology are described abovewith reference to block and flow diagrams of systems and methods and/orcomputer program products according to example implementations of thedisclosed technology. It will be understood that one or more blocks ofthe block diagrams and flow diagrams, and combinations of blocks in theblock diagrams and flow diagrams, respectively, may be implemented bycomputer-executable program instructions. Likewise, some blocks of theblock diagrams and flow diagrams may not necessarily need to beperformed in the order presented, or may not necessarily need to beperformed at all, according to some implementations of the disclosedtechnology.

These computer-executable program instructions may be loaded onto ageneral-purpose computer, a special-purpose computer, a processor, orother programmable data processing apparatus to produce a particularmachine, such that the instructions that execute on the computer,processor, or other programmable data processing apparatus create meansfor implementing one or more functions specified in the flow diagramblock or blocks. These computer program instructions may also be storedin a computer-readable memory that may direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meansthat implement one or more functions specified in the flow diagram blockor blocks. As an example, implementations of the disclosed technologymay provide for a computer program product, comprising a computer-usablemedium having a computer-readable program code or program instructionsembodied therein, said computer-readable program code adapted to beexecuted to implement one or more functions specified in the flowdiagram block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operational elements or steps to be performed onthe computer or other programmable apparatus to produce acomputer-implemented process such that the instructions that execute onthe computer or other programmable apparatus provide elements or stepsfor implementing the functions specified in the flow diagram block orblocks.

Accordingly, blocks of the block diagrams and flow diagrams supportcombinations of means for performing the specified functions,combinations of elements or steps for performing the specified functionsand program instruction means for performing the specified functions. Itwill also be understood that each block of the block diagrams and flowdiagrams, and combinations of blocks in the block diagrams and flowdiagrams, may be implemented by special-purpose, hardware-based computersystems that perform the specified functions, elements or steps, orcombinations of special-purpose hardware and computer instructions.

While certain implementations of the disclosed technology have beendescribed in connection with what is presently considered to be the mostpractical implementations, it is to be understood that the disclosedtechnology is not to be limited to the disclosed implementations, but onthe contrary, is intended to cover various modifications and equivalentarrangements included within the scope of the appended claims. Althoughspecific terms are employed herein, they are used in a generic anddescriptive sense only and not for purposes of limitation.

This written description uses examples to disclose certainimplementations of the disclosed technology, including the best mode,and also to enable any person skilled in the art to practice certainimplementations of the disclosed technology, including making and usingany devices or systems and performing any incorporated methods. Thepatentable scope of certain implementations of the disclosed technologyis defined in the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral language of the claims.

We claim:
 1. A method comprising: receiving, at a processor, privatedata corresponding to first user input at an input device operativelycoupled to the processor, wherein the private data is formatted forentry into a GUI of a data communications software, the GUI beingdisplayed at a display device coupled to the processor; receiving, atthe processor, an indication of second user input corresponding to atransmit-message functionality of the data communications software;transforming, by the processor, the private data, to create transformedprivate data; outputting, by the processor, the transformed privatedata, to the GUI of the data communications software; and responsive toreceiving the indication of the second user input, initiating, by theprocessor, transmission of the transformed private data by the datacommunications software.
 2. The method of claim 1, further comprising:outputting, for display at the display device, an overlay GUI orientedover the GUI of the data communications software and comprising at leastone user interface element overlaying a portion of the GUI of the datacommunications software for receiving private data, wherein the privatedata corresponding to the first user input is received by the at leastone user interface element, and the transformed private data is outputto the portion of the GUI of the data communications software forreceiving private data.
 3. The method of claim 2, wherein the at leastone user interface element overlaying the portion of the GUI of the datacommunications software for receiving private data mimics the appearanceof the portion of the GUI of the data communications software.
 4. Themethod of claim 3, wherein the at least one user interface elementmimicking the appearance of the portion of the GUI of the datacommunications software for receiving private data is visuallydifferentiated from the mimicked portion of the GUI by color.
 5. Themethod of claim 1, further comprising: outputting, for display at thedisplay device, an overlay GUI oriented over the GUI of the datacommunications software and comprising at least one user interfaceelement mimicking an appearance of, and overlaying, a portion of the GUIof the data communications software for initiating the transmit-messagefunctionality, wherein the second user input is received at the at leastone user interface element of the overlay GUI.
 6. The method of claim 1,wherein the transforming the private data includes encrypting theprivate data to create encrypted private data, and the transformedprivate data includes an indication of the encrypted private data. 7.The method of claim 1, wherein the processor is associated with a firstcomputing device and the transformed private data is a first transformedprivate message, the method further comprising: obtaining, from the GUIof the data communications software, a second transformed privatemessage, wherein the second transformed private message is received bythe first computing device and represents private data transformed at aprocessor of a second computing device remote from the first computingdevice; reverse-transforming, by the processor, the second transformedprivate data, to create second private data; and outputting, for displayat the display device, an indication of the second private data.
 8. Themethod of claim 7, further comprising: outputting, for display at thedisplay device, an overlay GUI oriented over the GUI of the datacommunications software and comprising at least one user interfaceelement overlaying a portion of the GUI of the data communicationssoftware for displaying private data, wherein the indication of thesecond private data is displayed in the at least one user interfaceelement.
 9. The method of claim 10, wherein the private data comprisesat least one of email, instant message, video, and voice data.
 10. Anon-transitory computer-readable medium that stores instructions that,when executed by at least one processor of a mobile computing device,causes the mobile computing device to perform a method comprising:presenting, over a textual communications app GUI being displayed by themobile computing device, an overlay GUI comprising at least one userinterface element overlaying a portion of the textual communications appGUI for receiving textual data; receiving, at the at least oneprocessor, plaintext data corresponding to first user input received atthe mobile computing device, wherein the textual data is formatted forentry into the portion of the textual communications app GUI forreceiving textual data; encrypting, by the at least one processor, theplaintext data, to create ciphertext data; receiving, at the at leastone processor, an indication of second user input received at the mobilecomputing device, the second user input corresponding to atransmit-message functionality of the textual communications app;directing, by the at least one processor, the ciphertext data, to theGUI of the textual communications app; and responsive to receiving theindication of the second user input, initiating, by the processor,transmission of a first message including the ciphertext data by thetextual communications app.
 11. The non-transitory computer-readablemedium of claim 10, further comprising: receiving, by the textualcommunications app, a second message including ciphertext data, from aremote computing device; receiving, by the processor, from the textualcommunications app GUI, the ciphertext data; decrypting, by the at leastone processor, the ciphertext data of the second message to revealplaintext data associated with the second message; and displaying, bythe computing device, an indication of the plaintext data associatedwith the second message.
 12. The non-transitory computer-readable mediumof claim 10, further comprising: receiving, by the textualcommunications app, a second message including ciphertext data, from aremote computing device; obtaining, by the processor, from the textualcommunications app GUI, a portion of the second message including anassociated ID tag and at least a portion of the ciphertext data;decrypting, by the at least one processor, based on a key correspondingto the ID tag, the at least a portion of the ciphertext data to revealplaintext data associated with the second message; and displaying, bythe computing device, an indication of the plaintext data associatedwith the second message.
 13. The non-transitory computer-readable mediumof claim 10, wherein the textual communications app is a client app foraccessing a public cloud service.
 14. The non-transitorycomputer-readable medium of claim 10, wherein the first message is anemail or an instant message.
 15. A system comprising: an overlay GUI forintercepting user input; a cryptographic key for encrypting plaintextdata; at least one memory operatively coupled to at least one processorand configured for storing data and instructions that, when executed byat least one processor, cause the system to perform a method,comprising: presenting, over a GUI of the target client app beingdisplayed by a mobile computing device, the overlay GUI, wherein theoverlay GUI comprises at least one user interface element mimicking theappearance of, and overlaying, a portion of the GUI of the target clientapp GUI for receiving private data; receiving, at the at least oneprocessor, plaintext data corresponding to first user input received atthe mobile computing device, wherein the private data is formatted forentry into the portion of the target client app GUI for receivingprivate data; encrypting, by the at least one processor, based on thecryptographic key, the plaintext data, to create ciphertext data;receiving, at the at least one processor, an indication of second userinput received at the mobile computing device, the second user inputcorresponding to a transmit-message functionality of the target clientapp; directing, by the at least one processor, the ciphertext data, tothe GUI of the target client app; and responsive to receiving theindication of the second user input, initiating, by the processor,transmission of a first message including the ciphertext data by thetarget client app.
 16. The system of claim 15, further comprising logicfor configuring the overlay GUI, the method further comprising:receiving an indication of a current app being displayed by the mobilecomputing device; and configuring, based on indication of the currentapp, the overlay GUI such that the at least one user interface elementmimics and overlays the portion of the GUI of the target client app GUIfor receiving private data, wherein the current app is the target clientapp.
 17. The system of claim 15, wherein the indication of the currentapp being displayed comprises GUI configuration data obtained from a UTAof the mobile computing device or OS extension.
 18. The system of claim15, wherein the system runs in an isolated process from the targetclient app, and transient and permanent data stored in the at least onememory is inaccessible to other client apps.
 19. The system of claim 15,wherein the overlay GUI runs in a virtual machine of the mobilecomputing device.
 20. The system of claim 14, where the overlay GUIexecutes on a virtual-reality device that in communication with theuser's mobile device that runs the target client app.